<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
</html>
<script type="text/javascript">
//3、计算两个日期时间差值(天数)
var a1 = new Date("2017-12-01");
	var b1 = new Date("2015-01-12");
	t = Math.abs(a1.getTime()-b1.getTime());
	var dayout = t/1000/60/60/24;
	console.log(dayout) ;

</script>